本論文首先提出一非對稱性類偶極圓形極化天線,此天線是被設計應用於5 ~ 6 GHz的無線區域網路 (WLAN)。阻抗頻寬1 GHz (5 ~ 6 GHz),3 dB軸比頻寬800 MHz (5.2 ~ 6 GHz),天線增益則介於3.2 ~ 5.1 dBic。 在本篇文章中也設計了一個應用於全球定位系統的圓形極化天線,除了使用非對稱性類偶極天線設計以外,並在天線與被覆金屬板間隔離空氣層。天線增益在1.575 GHz約6 dBic,應用於GPS以及WiMAX頻段的雙頻天線。
In this thesis, we first present a circularly polarized antenna of asymmetrical dipole-like structure. The antenna is designed at 5 ~ 6 GHz for WLAN band with an impedance bandwidth of 1 GHz (5 ~ 6 GHz) and with an axial-ratio bandwidth of 800 MHz (5.2 ~ 6 GHz). The gain of the antenna is between 3.2 and 5.1 dBic. A circularly polarized GPS antenna is also investigated. Besides using the asymmetrical dipole-like antenna, there is an air gap between the antenna and a back covered metal plate. The gain at 1.575 GHz is around 6 dBic. This antenna is demonstrated for dual band operation at GPS and WiMAX bands.